Paper products softening compositions

ABSTRACT

Provided herein are amphoteric surfactants derived from ethyleneamines, which surfactants are useful in treating paper, fibers, textiles, hair, and human skin, to impart softness-to-the-touch properties thereto.

TECHNICAL FIELD

[0001] This invention relates to compositions useful for treatingvarious surfaces including fibers, textiles, paper, hair, and humanskin. More particularly, it relates to compositions and methods fortreating metal, paper, and textiles which compositions comprise anamphoteric surfactant derived from ethyleneamines, long-chain fattyacids, and acrylic acid. According to one preferred form of theinvention the ethyleneamine used as a raw material from which thesurfactant is derived is tetraethylenepentamine.

BACKGROUND

[0002] U.S. Pat. No. 5,322,630 provides a method of acidizing asubterranean formation with an acqueous acid solution wherein the acidsolution contains corrosion inhibiting amounts of an amine derivativeprepared by reacting an unsaturated carboxylic acid with (a) fatty amineor polyamine, or (b) a fatty amido amine or polyamine, or (c) a fattyimidazoline amine or polyamine. The derivative is characterized by theabsence of primary amino groups, and preferably contains only tertiaryamino groups. Disclosed therein are amphoteric derivatives of a broadrange of fatty polyamines, fatty amidoamines, fatty imidazolines andpolyamines which are disclosed as being useful as oilfield corrosioninhibitors.

[0003] U.S. Pat. Nos. 6,004,914; 6,200,938; and 6,369,007 teachamphoteric derivatives of aliphatic polyamines, such asdiethylenetriamine or triethylenetetramine reacted with long chain fattyacids, esters or triglycerides from various natural or synthetic sourcesare effective in the softening/texture modification of substrates suchas paper, textiles, human skin surfaces and hair tresses, as well as inapplications for metal working and lubrication. The polyamines are firstreacted with fatty acids, esters or triglycerides derived from variousanimal, vegetable or synthetic sources ranging in molecular distributionfrom butyric through erucic acids (e.g. milkfat, soy bean oil, rapeseedoil) to form polyamines or imidazolines; they are then further reactedwith unsaturated or halogenated carboxylic acids, carboxylated epoxycompounds or acid anhydrides (e.g. acrylic acid, itaconic acid,chloroacetic acid, maleic anhydrides octadecenyl anhydride) to form thevarious amphoteric structures.

SUMMARY OF THE INVENTION

[0004] The present invention relates to amphoteric surfactants that areuseful in various applications including paper softener, fabricsoftener, metal working and lubrication. An amphoteric surfactant of thepresent invention may be made by reacting tetraethylene pentamine(“TEPA”) with 2.5 to 3.0 moles of a fatty acid to form an intermediateamide compound which is then converted to an amphoteric compound byreacting it with 1 to 2 moles of an unsaturated acid species selectedfrom the group consisting of: maleic acid, maleic anhydride, vinylsulfonic acid, 2-methyl vinyl sulfonic acid, allylsulfonic acid, andacrylic acid. Thus, the present invention concerns compositions ofmatter useful for treating paper, textiles, and human skin comprising anamphoteric surfactant represented by the formula:

[0005] in which x is any integer selected from the group consisting of4, 5, and 6; R₁ in each occurrence is independently any alkyl grouphaving between 5 and 25 carbon atoms, whether straight-chain, branched,cyclic, saturated or unsaturated; R₂ in each occurrence is independentlyselected from the group consisting of: 1) hydrogen; 2) any saturated orunsaturated aliphatic mono- or di-carboxylic acid moiety having one ormore carboxyl functional groups and having one or more straight-chain orbranched, saturated or un-saturated aliphatic chains containing from 2to 20 carbon atoms; 3) any saturated or unsaturated aliphatic monosulfonic acid moiety having one or more —SO₃H functional groups andhaving one or more straight-chain or branched, saturated or un-saturatedaliphatic chains containing from 2 to 20 carbon atoms; and 4) a radicalof the formula:

[0006] in which R₁ has the same meaning as that ascribed to it above.

[0007] According to another embodiment, a composition according to theinvention comprises a mixture of at least two components each of whichcomprise different amphoteric surfactants which are represented by theformula:

[0008] in which R₁ in each occurrence is independently any alkyl grouphaving between 5 and 25 carbon atoms, whether straight-chain, branched,cyclic, saturated or unsaturated; R₂ in each occurrence is independentlyselected from the group consisting of: 1) hydrogen; 2) any saturated orunsaturated aliphatic mono- or di-carboxylic acid moiety having one ormore carboxyl functional groups and having one or more straight-chain orbranched, saturated or un-saturated aliphatic chains containing from 2to 20 carbon atoms; 3) any saturated or unsaturated aliphatic monosulfonic acid moiety having one or more —SO₃H functional groups andhaving one or more straight-chain or branched, saturated or un-saturatedaliphatic chains containing from 2 to 20 carbon atoms; and 4) a radicalof the formula:

[0009] in which R₁ has the same meaning as that ascribed to it above.According to yet a further embodiment, the above-described mixturecomprises:

[0010] a) a first amphoteric surfactant, having a value for x of 4;

[0011] b) a second amphoteric surfactant, having a value for x of 5;

[0012] c) a third amphoteric surfactant, having a value for x of 6,

[0013] with the first amphoteric surfactant being present in any amountbetween 8.0% and 20.0%; the second amphoteric surfactant being presentin any amount between 25.0% and 45.0%; and the third amphotericsurfactant being present in any amount between 35.0% and 60.0%, with allpercentages being calculated on a weight basis with respect to all ofthe amphoteric surfactants present which are defined by the aboveformula.

DETAILED DESCRIPTION

[0014] An amphoteric surfactant of the present invention is exemplifiedby the use of TEPA as a raw material, and other amphoteric surfactantsaccording to the invention are readily prepared using the same generalprocedure but with ethyleneamines such as pentaethylenehexamine,hexaethyleneheptamine, heptaethyleneoctamine, etc. An amphotericsurfactant according to the invention may be prepared by first reactingTEPA as a starting material with 2.5 to 3 moles fatty acids, to form anintermediate substituted TEPA polyamide. According to one preferred formof the invention, 3 moles of fatty acid are reacted with 1 mole of TEPAto yield the triamide. According to a preferred form of the invention,the polyamide is subsequently reacted with 1 to 2 moles of anunsaturated acid species such as acrylic acid or vinylsulfonic acid toform an amphoteric surfactant. According to one preferred form of theinvention, 2 moles of acrylic acid are reacted with one mole ofpolyamide, which is preferably a triamide. The resulting amphotericcompounds are useful as softeners for tissue paper, fabrics, hair andskin. The resulting amphoteric compounds are also useful as lubricantsin metalworking.

[0015] The general reaction scheme for producing an amphotericsurfactant useful in accordance with the present invention is set forthbelow:

[0016] In reaction (I), one mole of tetraethylenepentamine is caused tobe reacted with three moles of the mono-carboxylic acid in which R maybe any C₁ through C₂₅ alkyl group, whether straight-chain, branched,cyclic, saturated or unsaturated. In the case of unsaturated carboxylicacids used as reactant with TEPA, the present invention contemplates theuse of both cis- and trans-isomers. According to one preferred form ofthe invention, the reactant carboxylic acid is oleic acid, although anyother carboxylic acid having between about 7 and 25 carbon atoms may beused, or mixtures thereof. The product of the reaction between threemoles of the carboxylic acid and TEPA is the triamide shown in formula(II):

[0017] in which the R portion is supplied by the oleic acid.

[0018] This structure represents the predominant product of suchreaction according to the invention. In practice, a mixture ofpositional isomers is formed with the carboxylic acid residue beingsubstituted upon the various possible positions of substitution havingan active hydrogen atom at which the acid function of the carboxylicacid is capable of reacting, as is known to those skilled in the art.When fewer than three moles of acid are reacted per mole of TEPA, theresulting product is a mixture of isomers substituted at the first andsecond; first and third; first and fourth; first and fifth; second andthird; and second and fourth positions. The present invention embracesall such positional isomers and mixtures thereof.

[0019] Subsequent reaction of the polyamide shown in formula (II) withan unsaturated acid, such as, but not limited to, acrylic acid accordingto the formula (III):

[0020] yields an amphoteric surfactant according to the invention, asdescribed generally by formula (0) previously shown, and shownstructurally in formula (IV):

[0021] for the case where one mole of acrylic acid is reacted. When anunsaturated sulfonate such as vinylsulfonic acid or allylsulfonic acidis employed, the carboxylic acid group in the above structure isreplaced by the group —SO₃H thus providing an amphoteric surfactant witha sulfonate anionic portion. The structure above represents thepredominant product of such reaction according to the invention. Inpractice, a mixture of positional isomers is formed with the acrylicresidue being substituted upon the various possible positions ofsubstitution having an active hydrogen atom at which the unsaturatedfunction of the acrylic acid is capable of reacting, as is known tothose skilled in the art. When more than one mole of acrylic or otherunsaturated carboxylic or sulfonic acid is reacted, more than one of thepossible positions is substituted. The present invention embraces allsuch positional isomers. Monomers other than acrylic acid may of coursebe employed in the role just described for acrylic acid, includingunsaturated acid species selected from the group consisting of maleicacid, maleic anhydride, vinyl sulfonic acid, 2-methyl vinyl sulfonicacid, and allylsulfonic acid.

[0022] According to one preferred form of the invention, oleic acid isreacted with TEPA at 144° C. for about 6-10 hours and is subsequentlyreacted with acrylic acid in the presence of propylene glycol orpolyethylene glycol at about 105° C. for about 8 hours, or until thereaction is complete. The structures of the reaction product are easilyconfirmed using NMR and IR spectroscopy.

[0023] The following examples are illustrative of the present inventionand should not be construed as being delimitive thereof in any way. Ingeneral, any polyalkylene polyamine can be reacted with a fatty acid toyield an amide which is subsequently reacted with acrylic acid to yieldan amphoteric surfactants useful in treating hair, skin, paper, textilesand fibers according to the invention.

EXAMPLE 1 Preparation of TEPA+3 Moles Oleic Acid (TEPA Triamide)

[0024] 505.8 grams (1.8 moles) of oleic acid is charged to a 1 L roundbottom flask equipped with a mechanical stirrer and nitrogen purge.113.6 grams (0.60 moles) tetraethylene pentamine (“TEPA”) is slowlyadded with stirring under nitrogen at such a rate that the temperatureis not permitted to exceed 120° C. Following the addition thetemperature of the contents of the flask are maintained at 120° C. for30 minutes, after which time the heat is increased to cause the reactorcontents to reach 144° C., at which temperature the reactor contents aremaintained for 6 hours further. Condensate is collected in a Dean-Starktrap (theoretical=32.4 ml). The reaction is considered to be completewhen the acid number is below 10 meq/gram (acid numbers referred to inthis specification are measured by titrating an aqueous sample usingaqueous base which is about 0.1 N to a phenolphthalein end point andcalculating the acid number using the relation:

meq/gram=((B)×(N)×56.1)/(weight of sample in grams)

[0025] in which B=the total number of milliliters of base used; and

[0026] N=the Normality of the base used.

[0027] The resulting product is a waxy solid at room temperature. Totalyield=93.0% of theoretical, as determined by NMR and IR spectra. Theresulting product is a waxy solid at room temperature. Total yield=93.0%of theoretical, as determined by NMR and IR spectra.

EXAMPLE 2 Preparation of TEPA Triamide Amphoteric Surfactant

[0028] To a 3-neck 1 L round bottom flask equipped with a mechanicalstirrer, nitrogen purge, and addition funnel is charged 130.6 grams ofpropylene glycol and 98.3 grams (0.1 moles) of the oleic acid triamideof TEPA prepared from example 1 above. The contents of the flask areheated with stirring to 90° C. until the contents became homogeneous.7.2 grams (0.1 mole) of acrylic acid are added slowly, and the contentsof the flask are maintained at 105° C. for 3 hours. Alternatively, thereaction may be terminated when at least 90% of the acrylic acid hasreacted, as determined by quantitative IR spectroscopy.

EXAMPLE 3 Preparation of Ethyleneamine E-100+3 Moles TOFA (E-100Triamide)

[0029] Ethyleneamine E-100 (Huntsman Corp.) is a mixture oftetraethylenepentamine (10-15% TEPA), pentaethylenehexamine (33-38%PEHA) and hexaethyleneheptamine (45-54% HEHA). 516.4 grams of tall oilfatty acid (“TOFA”) is charged to a 1 L round bottom flask. undernitrogen purge. 162.6 grams of Ethylenamine E-100 is slowly added withstirring under nitrogen, the temperature being kept below 120° C.throughout the addition. Following the addition, the temperature of thecontents of the flask is maintained at 120° C. for 30 minutes. Then thetemperature is increased to 144° C. and maintained at 144° C. for anadditional six hours. The reaction is considered to be complete when theacid number is below 10.

EXAMPLE 4 Preparation of Ethyleneamine E-100 Triamide AmphotericSurfactant

[0030] To a 3-neck 1 L round bottom flask equipped with a mechanicalstirrer, nitrogen purge, and addition funnel is charged 120.6 grams ofpropylene glycol and 98.3 grams (0.1 moles) of the oleic acid triamideof TEPA prepared from example 3 above. The contents of the flask areheated with stirring to 90° C. until the contents became homogeneous.6.5 grams (0.090 mole) of acrylic acid are added slowly, and thecontents of the flask are maintained at 105° C. for 3 hours.Alternatively, the reaction may be terminated when at least 90% of theacrylic acid has reacted, as determined by quantitative IR spectroscopy.

Softness Tests for Tissue Paper

[0031] One important aspect of tissue paper for use in personal caresuch as facial tissue and bathroom tissue is the softness of suchpapers. In order to evaluate the effect of a compound according to thepresent invention, several test solutions were made up as follows:

[0032] Sample 1: 48% (TEPA+3 moles oleic acid+2 moles acrylic acid) 52%propylene glycol.

[0033] Sample 2: 48% (TEPA+2.5 moles oleic acid+1.5 moles acrylic acid)52% propylene glycol.

[0034] Sample 3: 48% (TEPA+2 moles oleic acid+2 moles acrylic acid) 52%propylene glycol.

[0035] Sample 4: 48% (TEPA+2 moles oleic acid+1 moles acrylic acid) 52%propylene glycol.

[0036] Sample 5: 48% (TEPA+3 moles oleic acid+1 moles acrylic acid) 52%propylene glycol.

[0037] Sample 6: 70% of sample 1 mixed with 30% of SURFONIC® E-400 MO(“monooleate”).

[0038] Sample 7: 70% of sample 2 mixed with 30% of SURFONIC® E-400 MO.

[0039] Sample 8: 70% of sample 3 mixed with 30% of SURFONIC® E-400 MO.

[0040] Sample 9: 70% of sample 4 mixed with 30% of SURFONIC® E-400 MO.

[0041] Sample 10: 70% of sample 5 mixed with 30% of SURFONIC® E-400 MO.

[0042] Sample 11: pure SUFRONIC® E-400 MO (SURFONIC® products areavailable from Huntsman Corporation)

[0043] Control 1: 48% (diethylenetetramine “DETA”+2 moles TOFA (tall oilfatty acid)+1 mole acrylic acid)+52% propylene glycol.

[0044] Control 2: 70% of control 1+30% SUFRONIC® E-400 MO.

[0045] In the above samples, the terminology reminiscent of “(TEPA+2moles oleic acid+2 moles acrylic acid)” means the amphoteric surfactantproduced by reacting TEPA with 2 moles of oleic acid, and subsequentlyreacting the product thereof with 2 moles of acrylic acid. The variouscompositions descried above in samples 1-5 were prepared by simplemixing of the specified amount of glycol and amphoteric surfactant.Similarly, for examples 6-10 the specified amounts of materials wereblended together. SUFRONIC® E-400 MO is an ethoxylated oleic acidsurfactant available from Huntsman Company LLC of Houston, Tex.

[0046] Solutions for treating tissue paper were prepared by making up a1.0% solution of each of the above samples in water. Evaluations of theeffect of each solution were made by immersing a swatch of untreatedtissue in each of the 1.0% aqueous solutions containing the material inthe samples above. The treated tissue swatches were held in the solutionfor one minute, and withdrawn. The treated tissue swatches were thendried in an oven at 25° C. The tissues so treated were evaluated fortheir softness to the touch by several members of our research staff andeach given a rating based on the scale: 0=poor/harsh texture; 1=fair;2=good; 3=very good; 4=excellent/very soft texture. The results of thesoftness testing is tabulated in the table I below: TABLE I softnessfeel test results Sample ID Softness DI Water 0 Sample 6 2.4 Sample 72.4 Sample 8 1.2 Sample 9 1.8 Sample 10 3.8 Sample 11 1.4 Sample 5 4.0Control 1 2.5 Control 2 2.4

[0047] Sample 6 and sample 7 are comparable to the prior art; however,sample 10 and sample 5 are superior to the prior art. In the graph belowis the surface response curve for the above samples. It can be seen fromthe contour plot below of the softness test results that the maximumperformance occurs with 3 moles of oleic acid and 1 mole of acrylicacid:

[0048] Consideration must be given to the fact that although thisinvention has been described and disclosed in relation to certainpreferred embodiments, obvious equivalent modifications and alterationsthereof will become apparent to one of ordinary skill in this art uponreading and understanding this specification and the claims appendedhereto. Accordingly, the presently disclosed invention is intended tocover all such modifications and alterations, and is limited only by thescope of the claims which follow.

I claim: 1) A composition of matter useful for treating paper, textiles,and human skin comprising an amphoteric surfactant represented by theformula:

in which x is any integer selected from the group consisting of: 4, 5,and 6; R₁ in each occurrence is independently any alkyl group havingbetween 5 and 25 carbon atoms, whether straight-chain, branched, cyclic,saturated or unsaturated; R₂ in each occurrence is independentlyselected from the group consisting of: 1) hydrogen; 2) any saturated orunsaturated aliphatic mono- or di-carboxylic acid moiety having one ormore carboxyl functional groups and having one or more straight-chain orbranched, saturated or un-saturated aliphatic chains containing from 2to 20 carbon atoms; 3) a saturated or unsaturated aliphatic monosulfonic acid moiety comprising an —SO₃H functional group and having oneor more straight-chain or branched, saturated or un-saturated aliphaticchains containing from 2 to 20 carbon atoms; and 4) a radical of theformula:

 in which R₁ is defined as above. 2) A composition according to claim 1wherein R₁ in each occurrence may be independently derived from acarboxylic having an unsaturated alkyl carbon bond. 3) A compositionaccording to claim 1 wherein R₂ in each occurrence is independentlyderived from an acid selected from the group consisting of: acrylicacid, maleic anhydride, vinylsulfonic acid, allylsulfonic acid, 2-methylvinyl sulfonic acid, and maleic acid. 4) A composition of matter usefulfor treating paper, textiles, and human skin comprising a mixture of atleast two components each of which comprise different amphotericsurfactants which are represented by the formula:

in which x is any integer selected from the group consisting of: 4, 5,and 6; R₁ in each occurrence is independently any alkyl group havingbetween 5 and 25 carbon atoms, whether straight-chain, branched, cyclic,saturated or unsaturated; R₂ in each occurrence is independentlyselected from the group consisting of: 1) hydrogen; 2) any saturated orunsaturated aliphatic mono- or di-carboxylic acid moiety having one ormore carboxyl functional groups and having one or more straight-chain orbranched, saturated or unsaturated aliphatic chains containing from 2 to20 carbon atoms; 3) a saturated or unsaturated aliphatic mono sulfonicacid moiety comprising an —SO₃H functional group and having one or morestraight-chain or branched, saturated or un-saturated aliphatic chainscontaining from 2 to 20 carbon atoms; and 4) a radical of the formula:

 in which R₁ is defined as above. 5) A composition according to claim 4wherein one of the components of said mixture has the structure:

in which R in each occurrence is independently any alkyl group havingbetween 5 and 25 carbon atoms, whether straight-chain, branched, cyclic,saturated or unsaturated. 6) A composition according to claim 5 in whichthe carboxylic acid appendage on the nitrogen atom is derived fromacrylic acid. 7) A composition according to claim 4 wherein one of thecomponents of said mixture has the structure:

in which R in each occurrence is independently any alkyl group havingbetween 5 and 25 carbon atoms, whether straight-chain, branched, cyclic,saturated or unsaturated, and in which L is any alkyl group having anynumber of carbon atoms between about 2 and about 20, whetherstraight-chain, branched, or cyclic. 8) A composition according to claim4 wherein said mixture comprises: a) a first amphoteric surfactant,having a value for x of 4; b) a second amphoteric surfactant, having avalue for x of 5; c) a third amphoteric surfactant, having a value for xof 6, said first amphoteric surfactant being present in any amountbetween 8.0% and 20.0%; said second amphoteric surfactant being presentin any amount between 25.0% and 45.0%; and said third amphotericsurfactant being present in any amount between 35.0% and 60.0%, whereinsaid percentages are calculated on a weight basis with respect to all ofthe amphoteric surfactants present which are defined by said formula. 9)A process for treating a substrate comprising the steps of: a) providingan aqueous composition that comprises an amphoteric surfactant accordingto claim 1; and b) contacting said substrate with said aqueouscomposition. 10) A process according to claim 9 wherein theconcentration of said amphoteric surfactant is any concentration between0.10% and 5.00% by weight based upon the total weight of said aqueouscomposition. 11) A process for treating a substrate comprising the stepsof: a) providing an aqueous composition that comprises an amphotericsurfactant according to claim 4; and b) contacting said substrate withsaid aqueous composition. 12) A process according to claim 11 whereinthe concentration of said amphoteric surfactant is any concentrationbetween 0.10% and 5.00% by weight based upon the total weight of saidaqueous composition. 13) A process for treating a substrate comprisingthe steps of: a) providing an aqueous composition that comprises anamphoteric surfactant according to claim 7; and b) contacting saidsubstrate with said aqueous composition. 14) A process according toclaim 13 wherein the concentration of said amphoteric surfactant is anyconcentration between 0.10% and 5.00% by weight based upon the totalweight of said aqueous composition.